Publicações

July 01, 2019

The net primary productivity is one of the main indicators of an ecosystem’s health. The objectives of the present study were to assess the performance of machine learning techniques in net primary productivity modeling and to assess regional trends for the Brazilian territory. Net primary production was modeled using evapotranspiration estimates, the normalized difference vegetation index, hypsometry and meteorological data. The models adopted for estimating net primary productivity were stepwise regression, Bayesian regularized neural network and Cubist regression. A linear trend model was applied pixel by pixel in order to verify a significant change in net primary productivity across the Brazilian territory. The Cubist model performed best among the evaluated models, with root-mean-squared error of 135.6 g C m−2 year−1 and R2 equal to 0.78. While assessing the net primary productivity time series, an increased trend was observed for the Brazilian Savannah biome, which may be attributed to the replacement of some Savannah formations and degraded grasslands to agriculture. The developed model has shown a great potential for filling the gap of spatial net primary productivity data in large scales.

May 01, 2019

The attached microalgal biomass production in wastewater is promising for the development of biofilm reactors aimed at the economic separation and harvestingof biomass. However, the current impasse in the attached algal biomass production relies on the ability of materials to support such adherence. This study evaluated the effects of different support materials on the production and composition of algal biomass cultivated in domestic sewage. Durability and adherence of algal biomass to the threads of the support material were the most important criteria for choosing the material with the best performance. Three support materials were evaluated: cotton, nylon, and polyester. Polyester presented the best results in terms of durability; its resistance to friction tests was the highest, and even increased after its use in the experiment; this was associated with the high biomass production, mostly after the biomass inoculum (50.1 g∙m−2). This support also demonstrated greater development of nitrifying bacteria, which are essential for biofilm formationdue to the presence of filaments in their cells. As for biomass characterization, it was observed that the different support materials did not interfere in the composition of the cells present in the attached biomass.

April 01, 2019

This study approached the use of atmospheric emissions as a source of carbon for the cultivation of microalgae in high rate ponds (HRPs), continuously fed with domestic sewage pre-treated in a septic tank. To do so, two HRPs were used: one had CO2 at a concentration of 99.9% (HRP 1), and the other had gas from the combustion of gasoline (HRP 2). Biomass yield, sewage treatment efficiency and the economic viability of using these two sources were assessed. The results showed that the CO2 source did not influence the domestic sewage treatment or the yield and biochemical composition of biomass, since there was no statistical difference (p < 0.05) between the values measured for both ponds. The mean yield values were 6.00 and 6.12 g m−2 day−1, respectively for the HRPs 1 and 2. As for the mean concentrations of ammonia nitrogen and the percentages of removal of chemical oxygen demand (COD), they were in the average for both HRPs (26.4 mg L−1 and 31.2%). The negative Net Present Values (NPV) showed that in this study the investments for installing external CO2 sources are not economically viable for any of the two studied sources, when the biomass produced in the HRPs is used for the production of biofuels and as source of protein for animal feeding. The initial investments, allied to the prices of the biomass, were the factors that mostly influenced the economic analysis, contributing to the lack of attractiveness in this scale. Despite this, the use of atmospheric emissions along with domestic sewage as a cultivation medium means the biomass produced in this study has less environmental impact when compared to similar biomasses.

April 01, 2019

The objective of this study is to present a method for identifying zones susceptible to rainfall-induced landslides, based on field experiments in combination with strategic decision analysis through multi-criteria evaluation to obtain landslide susceptibility maps for areas where no landslide inventory maps are available. Field experiments were conducted to characterize runoff and water infiltration in different conditions of soil, land cover, and slope, as the occurrence of a combination of these factors is correlated with mass movements. An empirical model was used to transform at-site runoff information to a runoff map (spatial form). Spatial patterns were then utilized in a multi-criteria evaluation procedure, resulting in a digital model showing very low, low, moderate, high, and very high landslide susceptibility zones. Areas of high and very high landslide susceptibility corresponded to 17.6% and 8.6% of all areas classified as being at risk, respectively. Together, these classes accounted for 8% of approximately 6600 km2. We conclude that the use of this methodology allowed the identification of landslides induced by rainfall, and due to the nature of experimental-empirical modelling, we recommend that this method is replicated for other conditions.

February 20, 2019

The application of algal biomass in the soil represents an alternative of efficient use of fertilizers. In the present study, the environmental impacts generated by the application of 1 kg of nitrogen from the algal biomass (biofertilizer) were analyzed through life cycle analysis. Nitrogen was recovered from a meat processing industry effluent in a high-rate algal pond. Impacts related to the entire biofertilizer chain were mainly impacting on climate changes (115 kgCO2eq). Other categories (particle formation, terrestrial acidification, freshwater eutrophication and freshwater ecotoxicity) were not very representative. Biomass cultivation was the most critical step regarding energy and time consumption. On the other hand, the use of effluent as the culture medium for microalgae growth reduced impact categories, such as freshwater eutrophication. Results showed that microalgae cultivation and harvesting steps need to be technologically developed, especially when compared to a conventional fertilizer already established in the market. In order to make microalgae biofertilizer environmental advantageous, alternatives should be beforehand: i) the use of photovoltaic energy instead of hydropower energy; ii) the use of a nitrogen richer effluent; iii) and the consideration of an environmental compensation for the treatment of effluent can be accounted for, disregarding the biomass production stage.

January 01, 2019

TThe outbreak of sylvatic Yellow Fever (SYF) in humans during 2016-2017 in Brazil is one of the greatest in the history of the disease. The occurrence of the disease in areas with low vaccination coverage favoured the dissemination of the disease; therefore, it is necessary to identify the areas vulnerability to the YF virus (YFV) to assist in the adoption of preventive measures.

March 01, 2018

A construção civil é responsável por um elevado consumo de recursos naturais e também pela geração de uma grande quantidade de resíduos de construção e de demolição (RCD). Uma alternativa para o gerenciamento sustentável dos RCDs é a reciclagem para uso na própria construção civil, o que permite a redução da demanda de recursos naturais e dos custos, além de amenizar o impacto gerado pela disposição inadequada desses resíduos no meio ambiente. Diante desse cenário, o presente trabalho tem como objetivo analisar e selecionar áreas para a implantação de uma usina de reciclagem de RCD no Município de Viçosa, MG. Foram utilizadas técnicas de sistemas de informações geográficas (SIG) que permitiram avaliar áreas alternativas por meio da aplicação da análise multicritério, tendo sido selecionadas 23 áreas possíveis para implementação da unidade. A análise complementar com visitação in loco permitiu a seleção de 4 áreas consideradas mais adequadas por apresentarem acesso facilitado, baixos valores imobiliários, ausência de edificações ou uso futuro predefinido. A metodologia adotada se mostrou apropriada para auxiliar na tomada de decisão e na diminuição do tempo necessário para a escolha de áreas destinadas à reciclagem de RCD, podendo ser replicada em outros municípios.

August 01, 2018

The present study evaluated the cultivation of microalgae in a photobioreactor using effluents from the meat-processing industry, which had been previously treated at the primary and secondary levels. Scenedesmus sp. was the dominant genus in the phytoplankton community in both of the evaluated effluents. The different nutritional conditions affected the production of biomass, which reached 1,160 mg/L of volatile suspended solids (VSS) and 371 mg/L of VSS with cultivation in the primary (PE) and secondary effluents (SE), respectively. In both effluents, great removal efficiencies close to quantification limits were observed for ammoniacal nitrogen and soluble phosphorus. Regarding the accumulation of lipids, there were no considerable differences between the effluents. The highest lipid productivity that was observed in the PE, which reached 3.7 g/m²·d, was attributed to its larger production of biomass as a consequence of its better nutritional condition in relation to the SE.

February 26, 2018

The rapid expansion of eucalyptus cultivation necessitates studies that can identify areas amenable to the planting and development of its different varieties. This study therefore aimed to verify the suitability of two varieties of eucalyptus in the state of Espírito Santo, using Geographic Information Systems supported by strategic decision analysis. Mean precipitation, mean temperature, hydric deficit and land slope data were used as decision factors. These factors were submitted to fuzzy standardization, aggregated and compensated by the Weighted Linear Combination (WLC) process, resulting in the final aptitude mapping. For the reconciliation of conflict areas between the varieties, the Multi-objective Land Allocation (MOLA) module was used to maximize the suitability of the land for the objective. The WLC analysis allowed us to identify the suitability of the areas and with the use of the MOLA module it was possible to resolve the conflict of suitability between the two eucalyptus varieties. Most of the state of Espírito Santo is highly suitable for the the development of varieties. The northwestern region and part of the northern region presented less suitability for both analyzed eucalyptus varieties. Considering the 10,000 km2 most adaptable area for eucalyptus cultivation in the state of Espírito Santo, it was verified that the most suitable areas for planting the two eucalyptus varieties are located in the mountainous regions, part of the southern region and near the northeastern coast.

March 01, 2018

This study evaluated the operation of a hybrid anaerobic reactor fed with algal biomass cultivated in effluent from the brewery industry. Three stages of operation were distinguished during the 72 days of semi-continuous functioning of the reactor: Stage 1 (S1), in which algal biomass was used as substrate; Stage 2 (S2), in which 10% (v/v) of the algal biomass was substituted by olive mill wastewater(OMW); and Stage 3 (S3), in which algal biomass was heat pre-treated. During S1, a loss of solids was observed, with an increment of organic matter in the outlet. The substitution of 10% of the volume of algal biomass by OMW tripled the methaneproductivity obtained in the previous stage by digestion of pure algal biomass. Heat pre-treatment was not efficient in rupturing the cell wall, and consequently did not have any effect on the increase in biogas production. The complementarity of substrates in the assessed conditions led to better results than the pre-treatment of the algal biomass.

October 02, 2016

The accelerated process of urbanization coupled with lack of public policies directed toward effi cient planning, has led to the occupation of geotechnically unstable areas, contributing to the occurrence of natural disasters, such as landslides, which directly or indirectly aff ect the population located around the risk areas. This paper aims to use the potential of Geographic Information System (GIS) for mapping landslide susceptibility areas using the deterministic model Shallow Slope Stability Model (SHALSTAB) integrated with Multi Criteria Evaluation (MCE) in São Bartolomeu stream basin, located in Viçosa municipality, Minas Gerais State, Brazil. The methodology adopted in this work combines the results obtained by the SHALSTAB model for each predominant soil type in the basin (Latosols, Argisols and Cambisols) as one of conditioning factors to landslides, weighted with the factors of land use/cover, distance from roads and slopes profi le classes in the MCE. Using the technique of comparing by pairs AHP, it was generated a set of relative weights for each factor, subsequently aggregated in the procedures of Weighted Linear Combination (WLC) and Ordered Weighted Average (OWA). Three OWA scenarios were performed with low, medium and high risk, all with high compensation. Taking the landslides occurrence points reported to the Civil Defense Department of Viçosa, it was found that the best scenario was that of low risk and high compensation (risk: 0.63 and compensation: 80%), because most of this points were identifi ed in the areas of high and very high instability, obtained by integration of SHALSTAB model and MCE, unlike the application of the SHALSTAB model individually. It was also observed that the classes of medium, high and very high instability are located near or in urban areas and in the Latosols soil type. With the results of this work, was possible showed that the integration between SHALSTAB model and MCE enable mapping landslides susceptibility areas in a more coherent way with the reality, because it allows taking into account natural factors and human activities, both directly related to the occurrence of landslides.

October 02, 2016

n this investigation, chemical characteristics, higher, lower and net heating value, bulk and energy density, and thermogravimetric analysis were applied to study the thermal characteristics of three algal biomasses. These biomasses, grown as by-products of wastewater treatment in high-rate algal ponds (HRAPs), were: (i) biomass produced in domestic effluent and collected directly from an HRAP (PO); (ii) biomass produced in domestic effluent in a mixed pond-panel system and collected from the panels (PA); and (iii) biomass originating from the treatment effluent from the meat processing industry and collected directly from an HRAP (IN). The biomass IN was the best alternative for thermal power generation. Subsequently, a mixture of the algal biomasses and Jatropha epicarp was used to produce briquettes containing 0%, 25%, 50%, 75%, and 100% of algal biomass, and their properties were evaluated. In general, the addition of algal biomass to briquettes decreased both the hygroscopicity and fixed carbon content and increased the bulk density, ash content, and energy density. A 50% proportion of biomass IN was found to be the best raw material for producing briquettes. Therefore, the production of briquettes consisting of algal biomass and Jatropha epicarp at a laboratory scale was shown to be technically feasible.

January 01, 2018

The Southeast Region of Brazil has undergone major changes in land cover, especially after the eighteenth century. It is currently the most populous region of the country, highly urbanized, with a high degree of industrial and agricultural development. Extensive areas of native vegetation have been replaced by pastures, crops and urban areas, which have increased runoff, causing environmental, economic and social problems related to flooding. The objective of this study was to analyze effects of land cover changes in a basin with rural and urban characteristics on the flow of its main river. Hydrological data, orbital images, soils and topographical maps were used for this purpose. Based on the land cover maps for the years of 1989, 2001 and 2015, and on the hydrological modeling performed using the Hec-HMS 4.1 software, scenarios were simulated and showed that the land cover changes in this basin significantly affect the flow behavior of the main river. The simulated runoff was calibrated using the data observed in the field during 2001, and validation was performed using data from 1989. After the calibration and validation processes, a scenario was simulated where the rainiest month of the whole series measured by the rainfall station (during December 1989) acted on the land cover of 2015. There was an increase in pasture areas and impermeable spaces in the basin, which caused a decrease in infiltration and an increase in surface runoff, and also an increase in the flow peaks and a reduction in the time of concentration. The hydrological modeling was satisfactory, since the uncertainties related to the simulation were low

January 01, 2018

 The environmental fragility analysis evaluates the susceptibility of an environment to degradation. Thus, the goals of this work are to analyze and map the environmental fragility of the Lapa Grande State Park (PELG), Brazil, and its buffer zone (ZA) and also quantify the changes in the vegetation cover before and after the implementation of the PELG. The environmental fragility was evaluated through multicriteria analysis using the factors: slope, geology, pedology and land use and land cover. The changes in the high vigor vegetation cover were determined from the normalized difference vegetation index (NDVI) for 1996, 2006 and 2016. It was verified that the central-east and northeast regions of the PELG presented the greatest environmental fragilities in 1996, and significant reductions in the areas with high and very high fragility were observed in 2006 and 2016 due to the increase in the vegetation cover after the implementation of the PELG, which was more expressive in the park area than in the ZA. The increase of 20.7% of 2006 to 2016 in the vegetation with greater vigor, proved the importance of the creation of a conservation unit.

January 01, 2018

High rate algal pond (HRAP) was evaluated according to its energy potential and productivity by two rates, net energy ratio (NER) and specific biomass productivity. All energy inputs were calculated according to one HRAP with pre-ultraviolet disinfection treating anaerobic domestic sewage. The outputs were calculated for two energetic pathways: lipid and biogas production for the raw biomass (RB) and biomass after lipid extraction. The non-polar lipid content in dry biomass was 7.6% reaching a daily lipid productivity of 0.2 g/m2·day and the biogas production potential was 0.20 m3/kg solids. For the biomass after lipid extraction, the biogas production reached 2.6 m3/kg solids. NER values of 10−3 for the RB were similar for lipids and biogas routes. The specific biomass productivity was 0.7 mg/kJ. For the residual biomass, after lipid extraction, NER value was 10−2 for the integrated route (lipids + biogas) and the specific biomass productivity of the extracted biomass was 0.4 mg/kJ. The best energetic pathway was to integrate both lipids and biogas route.

January 01, 2018

The failure of the mining tailings dam in Mariana, Minas Gerais, Brazil, was the largest disaster of its type in Brazil, generating serious environmental and socioeconomic problems. The aim of this study was to identify potential sites for the disposal of the tailings that accumulated along the watercourses affected by the dam failure in the municipalities of Mariana and Barra Longa, as well as to quantify the area affected by the tailings. To quantify the area affected by the tailings dam failure, the Land Change Modeler (LCM) tool was used to verify the changes in land use and land cover that occurred in the periods before and after the environmental impact. For the identification of the suitable sites for tailings disposal, multicriteria analysis was performed using the Idrisi Selva® software and considering three scenarios to identify potentially affected areas through the application of the weighted linear combination (WLC) and ordered weighted average (OWA) techniques. In scenario 1, the WLC technique was applied, considering average risk and high compensation. In scenarios 2 and 3, the OWA technique was applied, with high risk and high compensation for scenario 2 and low risk and high compensation for scenario 3. The highest suitability value for tailings disposal was identified in scenario 2, which obtained the maximum value of 213 on a scale of 0–255, while for the scenarios 1 and 3, the suitability values were 158 and 124, respectively. The largest site for the tailings dam identified in the analysis for the municipally of Mariana has a size of 0.25 km2 and obtained a suitability value of 207. In the municipally of Barra Longa, the largest site identified has a size of 0.037 km2, with maximum suitability value of 209. In relation to the changes in land use and cover, it was verified that the vegetated areas, composed mainly of riparian forest and pasture, presented greater losses as a consequence of the dam failure, with reductions of 11.99 and 4.81 km2, respectively, demonstrating that the dam rupture disaster has caused serious damage to the environment and the population living in the region.

January 01, 2017

In this study, biomass production and domestic sewage treatment in hybrid systems under bacterial-microalga consortia were assessed. Biomass was grown suspended in the growth media of high-rate ponds (HRPs) and attached in biofilm reactors (BRs). These hybrid systems were operated with and without the addition of CO2 (HS2 and HS1, respectively) in the HRP growth media. The performances of these systems were compared with that of a conventional HRP with CO2 supplementation. Regarding sewage treatment with microalgae and bacteria consortia, the three systems showed no significant differences in the removal of organisms associated with faecal contamination, organic matter and most nutrients. However, nitrate levels were increased in the hybrid systems due to the presence of BRs. There were no differences in algal biomass production among the three systems, which remained in the 0.6–0.7 g m−2 range. HS1 showed the highest total biomass production of 101.31 g m−2 at a production rate of 6.79 g m−2 day−1. The BR of HS1 was able to supply the necessary CO2 and therefore no additional gas supplementation was required. This result indicates that a conventional HRP with CO2 supplementation can be replaced by a hybrid system with biofilm reactor, with additional advantages of resources saving, operational simplicity and easier harvesting.

January 01, 2017

This study evaluated the effect of high-rate ponds (HRPs) of different depths (20, 30 and 40 cm) on the carbon assimilation by microalgae cultivated in domestic sewage. The efficiency of the dissolution provided by the carbonation column and the carbon release to the atmosphere through the movement of the paddle wheels were also investigated. Dissolution efficiencies of 50%, 48% and 46% were obtained in the HRPs of 20, 30 and 40 cm depth, respectively. These differences can be attributed to the time necessary to recirculate the volume of each HRP in the carbonation column. The volumetric mass transfer coefficients regarding the release to the atmosphere were 0.0007, 0.0005 and 0.0004 min−1 for the 20, 30 and 40 cm HRPs, respectively. The carbon assimilation by the biomass was inversely proportional to depth, with values of 90%, 72% and 68% for the 20, 30 and 40 cm HRPs, respectively. Chlorophyll-a concentration was also higher in the 20 cm HRP. The radiation attenuation at the beginning of the operation was similar among the treatments, resulting in a greater fraction of the pond depth with available radiation in the 20 cm HRP.

November 01, 2017

This study evaluates the application of biomass produced from the treatment of domestic sewage in high-rate ponds (HRPs) as feedstock for the production of bio-oil via hydrothermal liquefaction (HTL). The effects of reaction time, temperature, and biomass/water ratio on the yield of bio-oil were assessed. In addition, a balance of carbon and nitrogen among the products (bio-oil, aqueous phase, solid residue, and gas) was carried out, in order to evaluate the quality of the bio-oil and possibilities for increasing value from the byproducts. In a 15-min operation at 300 °C with biomass/water ratio of 1/10 (w.w−1), the bio-oil yield was of 44.4% (Dry Ash Free - daf-basis). Under every condition tested, the solid residue was the most abundant byproduct, mostly due to the high ash content in the biomass. The minimum nitrogen recovery in the bio-oil was 57%, obtained in the operation at 275 °C, which is considered the main disadvantage of the process. The use of biomass directly after its production may result in an excessive consumption of energy due to the high water content. However, the need for drying is reduced when compared to other microalgal-based bioenergy production processes, potentially achieving a positive energy balance in the HTL.

January 01, 2017

Extreme rainfall data are usually scarce due to the low frequency of these events. However, prior knowledge of the precipitation depth and return period of a design event is crucial to water resource management and engineering. This study presents a model-based selection approach associated with regional frequency analysis to examine the lack of maximum daily rainfall data in Brazil. A generalized extreme values (GEV) distribution was hierarchically fitted using a Bayesian approach and data that were collected from rainfall gauge stations. The GEV model parameters were submitted to a model-based cluster analysis, resulting in regions of homogeneous rainfall regimes. Time-series data of the individual rainfall gauges belonging to each identified region were joined into a new dataset, which was divided into calibration and validation sets to estimate new GEV parameters and to evaluate model performance, respectively. The results identified two distinct rainfall regimes in the region: more and less intense rainfall extremes in the southeast and northwest regions, respectively. According to the goodness of fit measures that were used to evaluate the models, the aggregation level of the parameters in clustering influenced their performance.

January 01, 2016

With the objective of promoting nature conservation, this study proposes an environmental zoning for a protected area that contains part of the remaining Atlantic Forest, a global hotspot that is home to several endangered species of flora and fauna. Conflicting therewith, the protected area is an important tourist attraction in the region and receives many visitors throughout the year. For the zoning preparation, the main factors and constraints of each objective (ecotourism and conservation) are established, and a multi-criteria analysis is used, in addition to the MOLA (Multi-Objective Land Allocation) algorithm, to establish the most suitable areas for each use. Extreme protection areas are defined through the intersection of endemic vegetation and soils and altitudes above 1,500 m. Thus, a fraction of 18% is obtained for extreme protection, 59% for conservation, and 23% for areas destined for ecotourism development. The results demonstrate the advantages of using these methods, due to their simplicity, which can support administrators in planning the protected area. The zoning is in accordance with the International Union for Conservation of Nature (IUCN) recommendation because the conservation area corresponds to approximately 77% of the park area, reinforcing the suitability and applicability of the methodology that is used for the zoning of a protected area.

January 01, 2016

The objective of this study was to assess the energy potential, in terms of lipids and biogas, of the algal biomass cultivated in a photobioreactor using effluent from a meat processingplant (primary effluent = after the flotation unit and secondary effluent = after the activated sludge unit) as culture medium. Among the tested routes, the objective was to define the best one for energy use of the biomass and, in order to incorporate the concept of biorefinery, the biogas production was assessed with and without the previous lipid extraction. After 6 days of operation, the biomass cultivated in both effluents presented similar lipid content (7.0 and 6.1%), accounting for mean lipid productivities of 10.0 mg/L·d for the primary effluent and 3.4 mg/L·d for the secondary effluent. The methane production potential (MPP) of the post-flotation biomass was 0.44 m3 biogas/kg of total volatile solids (TVS) and of the post-activated sludge 0.28 m3 biogas/kg TVS. For the biomass after lipid extraction, the MPP was 2.38 m3 biogas/kg TVS for cultivation in the post-flotation effluent and 2.26 m3 biogas/kg TVS in the post-activated sludge effluent. None of the energy routes presented a net energy ratio (NER) higher than one. The energy gain with production of biogas after the lipid extraction was small, although higher NER values were obtained for this pathway. The biogas production from raw biomass, regardless of the culture medium, was the most favorable energy route.

January 01, 2016

Current human settlements are characterized by disorganized urbanization and high population densities, which can impact the landscape and the environment. Soil transport leads to erosion and aggradation of water bodies and increases landslide susceptibility in regions with more uneven topographies. Landslides are the most common environmental accidents and have caused the most deaths; one example is the incident that occurred in the mountainous region of the state of Rio de Janeiro (Brazil) in January 2011. Mapping the predisposition or susceptibility of components of the physical environment to landslides provides an integrated view of the characteristics and physical processes that act within a region. Therefore, the objective of this study is to evaluate the urban expansion proposal of Baptista (Avaliação da suscetibilidade aos movimentos de massa, erosão e escoamento superficial em Nova Friburgo, RJ, 2009) and compare it with the areas affected by the mega-disaster of 2011 using hierarchical decision analysis and a GIS toolkit. The results show that landslides did not affect the areas selected for urban expansion, i.e., the method was useful for identifying the areas that were most susceptible to landslides prior to the disaster.

January 01, 2016

Current human settlements are characterized by disorganized urbanization and high population densities, which can impact the landscape and the environment. Soil transport leads to erosion and aggradation of water bodies and increases landslide susceptibility in regions with more uneven topographies. Landslides are the most common environmental accidents and have caused the most deaths; one example is the incident that occurred in the mountainous region of the state of Rio de Janeiro (Brazil) in January 2011. Mapping the predisposition or susceptibility of components of the physical environment to landslides provides an integrated view of the characteristics and physical processes that act within a region. Therefore, the objective of this study is to evaluate the urban expansion proposal of Baptista (Avaliação da suscetibilidade aos movimentos de massa, erosão e escoamento superficial em Nova Friburgo, RJ, 2009) and compare it with the areas affected by the mega-disaster of 2011 using hierarchical decision analysis and a GIS toolkit. The results show that landslides did not affect the areas selected for urban expansion, i.e., the method was useful for identifying the areas that were most susceptible to landslides prior to the disaster.

January 01, 2016

The accelerated process of urbanization coupled with lack of public policies directed toward effi cient planning, has led to the occupation of geotechnically unstable areas, contributing to the occurrence of natural disasters, such as landslides, which directly or indirectly aff ect the population located around the risk areas. This paper aims to use the potential of Geographic Information System (GIS) for mapping landslide susceptibility areas using the deterministic model Shallow Slope Stability Model (SHALSTAB) integrated with Multi Criteria Evaluation (MCE) in São Bartolomeu stream basin, located in Viçosa municipality, Minas Gerais State, Brazil. The methodology adopted in this work combines the results obtained by the SHALSTAB model for each predominant soil type in the basin (Latosols, Argisols and Cambisols) as one of conditioning factors to landslides, weighted with the factors of land use/cover, distance from roads and slopes profi le classes in the MCE. Using the technique of comparing by pairs AHP, it was generated a set of relative weights for each factor, subsequently aggregated in the procedures of Weighted Linear Combination (WLC) and Ordered Weighted Average (OWA). Three OWA scenarios were performed with low, medium and high risk, all with high compensation. Taking the landslides occurrence points reported to the Civil Defense Department of Viçosa, it was found that the best scenario was that of low risk and high compensation (risk: 0.63 and compensation: 80%), because most of this points were identifi ed in the areas of high and very high instability, obtained by integration of SHALSTAB model and MCE, unlike the application of the SHALSTAB model individually. It was also observed that the classes of medium, high and very high instability are located near or in urban areas and in the Latosols soil type. With the results of this work, was possible showed that the integration between SHALSTAB model and MCE enable mapping landslides susceptibility areas in a more coherent way with the reality, because it allows taking into account natural factors and human activities, both directly related to the occurrence of landslides.

January 01, 2016

In this investigation, chemical characteristics, higher, lower and net heating value, bulk and energy density, and thermogravimetric analysis were applied to study the thermal characteristics of three algal biomasses. These biomasses, grown as by-products of wastewater treatment in high-rate algal ponds (HRAPs), were: (i) biomass produced in domestic effluent and collected directly from an HRAP (PO); (ii) biomass produced in domestic effluent in a mixed pond-panel system and collected from the panels (PA); and (iii) biomass originating from the treatment effluent from the meat processing industry and collected directly from an HRAP (IN). The biomass IN was the best alternative for thermal power generation. Subsequently, a mixture of the algal biomasses and Jatropha epicarp was used to produce briquettes containing 0%, 25%, 50%, 75%, and 100% of algal biomass, and their properties were evaluated. In general, the addition of algal biomass to briquettes decreased both the hygroscopicity and fixed carbon content and increased the bulk density, ash content, and energy density. A 50% proportion of biomass IN was found to be the best raw material for producing briquettes. Therefore, the production of briquettes consisting of algal biomass and Jatropha epicarp at a laboratory scale was shown to be technically feasible.

January 01, 2015

Greywater reuse is one of the main alternatives for reducing potable water consumption in households, industries and commercial buildings. Airport complexes need large amounts of water to maintain their operation routine, and replacing potable water with greywater may represent significant savings of financial and environmental resources. The objectives of this study were to discuss aspects related to greywater reuse in airports of different regions, as well as to present a case study of an airport in Brazil. Greywater treatment and reuse are quite common worldwide, although not many airports have already implemented such practice. Even though several sophisticated technologies have been widely used in some airports, treating source-separated effluent requires simple techniques and facilitates reuse. The case study evaluated a system consisting of an anaerobic filter followed by ultraviolet disinfection. The results were satisfactory according to less strict reuse standards and an economic analysis showed that in five years the cost of the investment will be returned. Due to its simple operation, the system is mostly indicated for small and mid-size airports, or for decentralized treatment in large airports. Greywater reuse must increasingly become part of a set of integrated actions toward the rational use of water, since this type of effluent represents an alternative source for non-potable uses, with extensive applicability in airports.

January 01, 2015

Using multivariate statistical tools, the composition of the phytoplankton community was related to the characteristics of the domestic sewage used as culture medium in three high rate ponds (HRPs) submitted to different solar radiation levels. A total of 32 genera of phytoplankton were identified in the ponds; the class Chlorophyceae was the most abundant during the entire sampling period, with a larger number of individuals of the genus Desmodesmus in the summer and fall, and of the genus Chlorella in the winter and spring. The lowest occurrence of phytoplankton was observed in the fall, with behavior similar to the evolution of solar radiation throughout the year. Blocking over 30% of the solar radiation allowed for less variability of the phytoplankton community and favored the growth of biomass with higher density of individuals, as well as higher concentrations of chlorophyll-aand dissolved oxygen. On the other hand, the pond with 80% of shading presented the lowest mean density of organisms; from the perspective of wastewater treatment, however, it can be considered the most efficient in terms of organic matter and nutrient removal. According to the regression analysis, the algal biomass in HRPs can be maximized mostly if we consider the positive effect of carbon and phosphorus and the limiting effect of nitrogen and non-biodegradable organic load. For the conditions evaluated in this study, the photoinhibition phenomenon was not observed. Other aspects such as competition with other microorganisms for space and nutrients, or predation by zooplankton, seemed to be more significant for the growth and development of algal biomass.

January 01, 2015

The objective of this study was to assess the effect of different solar radiation intensities on nitrogen assimilation by a consortium of bacteria and microalgae grown in pilot scale high rate ponds (HRP) treating domestic wastewater. The HRPs received effluent from an anaerobic reactor. The experiment was carried out under tropical climate conditions. A total of five HRPs were used; four of them were covered with shading screens that blocked 9%, 18%, 30% and 60% of the incident solar radiation. Nitrification was the main process for nitrogen removal/transformation in all HRPs and the volatilization of ammonia nitrogen occurred in levels below the expected range due to low pH values. The organic nitrogen concentration followed the same trend of the biomass production, but no statistical difference was found between the 60% screen HRP and the uncovered one, which led to the conclusion that the intensity of the photosynthetically active radiation does not compromise nitrogen assimilation, since the bacterial biomass may develop in conditions that are unfavorable to the growth of microalgae. Moreover, other aspects, such as CO2 addition, may reduce nitrogen losses by volatilization and denitrification, as well as contribute to recover this nutrient through biomass assimilation.

January 01, 2015

The production of different species of microalgae in consortium with other micro-organisms from wastewaters may represent an alternative process, to reduce the costs, for obtaining biofuels. The aim of this study was to evaluate the influence of pre-ultraviolet disinfection (UV) in the production of lipids from biomass produced in high rate ponds. Two high rate algal ponds were evaluated: a pond that received domestic sewage without disinfection and the other receiving domestic sewage previously disinfected by UV radiation (uvHRAP). The UV disinfection did not lead to significant differences in fatty acid profile and total lipid productivities, although it increased algal biomass concentration and productivity as well as lipid content. Moreover, the overall biomass concentrations and productivities decreased with the UV disinfection, mostly as a consequence of a loss in bacterial load. We thus conclude that uvHRAP disinfection may represent a potential strategy to promote the cleaner and safer growth of algal biomass when cultivated in consortium with other micro-organisms. Mainly regarding the use of wastewater as culture medium, together with a cheaper production of lipids for biodiesel, pre-disinfection may represent an advance since extraction costs could be significantly trimmed due to the increase in lipid content.

January 01, 2015

Knowing the influence of land use/land cover changes on the hydrological behavior of a subwatershed is essential to land use planning. The Alto Paraguaçu Watershed is a major producer of fruits and vegetables, and currently the largest producer of English potato in the north/northeast of Brazil. The water availability in the region can be considered the limiting factor to the expansion of agricultural frontiers. Therefore, in order to assess the influence of land use/land cover on the quality and quantity of the water resources in the subwatershed, three sampling campaigns were carried out (two in the rainy season and one in the dry season) at ten points throughout the watershed, as well as the hydrological analysis and land use/land cover changes assessment for both seasons. The objective was to relate land use/land cover indicators with hydrological indicators in order to fit a model to predict water changes in the studied subwatershed. The results showed that the changes that occurred in land use/land cover for the development of the current agriculture have significantly impacted the hydrological behavior in the Alto Paraguaçu watershed. It was possible to observe that the quality and quantity of water were directly influenced by the anthropization process. This study highlights the importance of suitable land use/land cover for the conservation of water resources.

January 01, 2015

A integração de sistemas de informação geográfica com os métodos de decisão multicritério, vem proporcionando inúmeros benefícios para a resolução de problemas de planejamento urbano. Nesse sentido este trabalho apresenta a metodologia utilizada na avaliação e seleção de áreas para a implantação de uma universidade e de um loteamento universitário no município de Patos de Minas - MG. Foram encontrados um local para o loteamento com área de 25,83 ha, e um para a universidade com uma área de 31,47 ha, ambos com risco médio e alta compensação. Os resultados obtidos revelam que o uso da ferramenta SIG associada a análise multicritério são eficientes na escolha de locais para a implantação de empreendimentos que causarão impactos no ambiente a ser instalado.

Acesse: http://lattes.cnpq.br/4128051734077960

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